1. Field of the Invention
This invention relates to an apparatus for use as either a rotary pump for liquids or a compressor for gases, and more particularly to a housing which includes a cam gear having gear teeth in rolling contact with rollers of a roller gear and which, upon rotation of the cam gear and roller gear, the fluids supplied through an inlet port is trapped in a moving chamber existing between adjacent gear teeth and portions of the internal wall of the housing in proximate contact with the adjacent gear teeth and in a moving pocket existing between adjacent rollers and a portion of the internal wall of the housing in contact with the adjacent rollers thereby transporting the fluid to an outlet port at an increased pressure.
2. Related Invention
See related U.S. Application entitled Cam Gear Assembly, Ser. No. 814,411, filed Dec. 23, 1991, which discusses the fabrication and operation of the cam-roller gear system.
3. Information Disclosure Statement
Rotary pumps for pressurizing liquid and rotary compressors for pressurizing gas are a positive-displacement type of apparatus which operate without the need for valves on either the suction and dischage ports. Gear pumps utilizing a type of straight spur gear are presently utilized. However, the disadvantages of the present gear pumps include a high level of noise created during operation and low mechanical efficiency. Low efficiency is due to the fact that liquid trapping between gear and pinion gear teeth during the double contact therebetween (meshing) may cause backlash displacement during operation of the pump and a portion of high pressure fluid may leak back to the low pressure side through the backlash of the gear teeth. Backlash displacement may also occur when the pump is not in operation. Also, the line of contact between mating gears has a sliding component, and leakage may occur across the contact line. Thus, such gear pump apparatus can not be used as a compressor of gaseous fluids.
Another disadvantage of the gear pump is that for a given gear size, displaced volume is increased by increasing the addendum short of creating interference of mating gears. Other rotary pumps and compressors, such as the two- or three-lobe pump and compressor are constructed with external pilot gears since power can not be transferred between the shafts themselves. Thus, leakage usually occurs across the sliding contact line of the impeller and housing at high pressure.
Therefore, the principal object of the present invention is to provide a mechanism for a rotary pump-compressor which operates without the backlash of the prior art devices and which also does not require external pilot gears for operation.
Another object of the present invention is to replace the line of contact of the sliding gear teeth of the prior art devices by a line of contact utilizing a compressed rolling action of the present invention.
Another object of the present invention is to provide a rotary pump and a rotary compressor apparatus with reduced operational friction during meshing of the gears.
Another object of the present invention is to provide a rotary pump-compressor which has a large displacement volume for a given gear size.
Another object of the present invention is to provide a rotary pump-compressor which substantially eliminates the trapping of fluids between mating gears thereby increasing efficiency.
The preceding objects should be construed as merely presenting a few of the more pertinent features and applications of the invention. Many other beneficial results can be obtained by applying the disclosed invention in a different manner or modifying the invention within the scope of the disclosure. Accordingly, other objects and a fuller understanding of the invention may be had by refering to both the summary of the invention and the detailed description, below, which describe the preferred embodiment in addition to the scope of the invention defined by the claims considered in conjunction with the accompanying drawings.